The present invention relates to a method of reducing the severity hip dysplasia in animals, and including a dog food composition which has been found to be highly effective for this purpose.
Canine hip dysplasia is a coxofemoral joint deformity which is a common problem in veterinary medicine. The disease affects many types of dogs but is particularly pronounced with breeds of dogs which are large in size, such as dogs that weigh more than 35 pounds. Generally, larger the size of the particular breed of dog involved, the higher the incidence of hip dysplasia. Canine hip dysplasia is a disease that occurs in young animals, such as puppies, and affects the dog for its entire lifespan.
Hip dysplasia in the dog has also been recognized as a hereditary disease that is characterized by laxity of the hip joints and a degeneration of tissues in the joint. Laxity of the hip joint begins a cycle, in which movement by the animal and force applied to the joint forces the femoral head into an abnormal position. The abnormal positioning of the femoral head results in erosion of the joint cartilage, fibrillation of the round ligament and inflammatory changes in the synovial membrane. The end result of joint laxity is an abnormally shallow acetabulum and a flattened femoral head.
Clinically, the disease is highly variable in dogs ranging from minimal clinical signs in some dogs to symptoms of a crippling disease in others. In addition, the severity of the clinical signs does not necessarily correlate with radiographic measurement or pathologic severity of the condition itself. Differences in breeds of dogs, as well as individual temperament of the dogs, can also affect the clinical signs of the disease.
For the most part, diagnosis of hip dysplasia is made by a standardized radiographic examination, which has been found to be more than 70% accurate, with an even higher degree of accuracy when the dogs age is closer to 2 years.
It has been recognized that most cases of canine hip dysplasia develop within the first two years of life. While long term breeding programs might reduce the severity of hip dysplasia in certain breeds of dogs, it is equally apparent that environmental factors during the first two years of growth may also be a contributing cause.
The exact nature of the environmental factors that might influence the severity or occurrence of hip dysplasia in dogs at the present time is not entirely known. There are a number of factors which have been considered. One of these factors is the influence of hormonal balance on the development of joint laxity. At the present time, endogenous hormone balance has not proven to be significantly involved in hip dysplasia with dogs. Studies have also been conducted in which the dogs were confined during part of the growth cycle in order to result in a lower occurrence of hip dysplasia, but this has also given conflicting results. Rapid weight gain has also been investigated and had been thought to be prominently associated with occurrence of canine hip dysplasia, but to date has not proven to be a primary cause.
The influence of the diet on the occurrence of canine hip dysplasia during the first year of growth has also been evaluated by various investigators. It has been reported for example, that hip dysplasia was accelerated by feeding a high carbohydrate diet and was ameliorated by feeding a high meat or all meat diet. The oral administration of ascorbic acid and its effect on canine hip dysplasia has also been investigated and it was determined that this did not significantly affect the incidence of canine hip dysplasia in dogs.
It is therefore an object of the present invention to provide a method for reducing the severity of hip dysplasia in animals such as dogs, by administering a diet which has found to be effective for this purpose.
It is another object of the present invention to provide a method of reducing the severity of hip dysplasia in dogs by the control of various nutritional factors in the diet of the animal during the early stages of life.
It is a further object of the present invention to provide a nutritionally balanced dog food composition which has been found to substantially reduce the severity of hip dysplasia in dogs.
It is a still further object to provide a nutritionally balanced dog food composition which may be fed to the animals during the first years of growth and result in less severity of hip dysplasia as the dog matures.